1. Field
Disclosed herein is a sidewall construction of a casting mold to be used in casting of concrete elements and being fixed to the casting bed by means of magnets.
2. Description of Related Art
Detachable sidewall constructions of casting molds for elements cast of concrete are known in the art, said sidewall constructions being equipped with different fixing solutions. The sidewalls can be positioned to the casting bed at desired places, depending on the size and form of the product to be cast.
When casting wall elements of concrete, the flat mold to be used is in general a table or a tipping mold equipped with sidewalls. A casting machine moves above the table and batches the concrete mix to the mold. After the concrete is hardened, the table is tipped about a tilting axle provided on one side of the table, into an almost upright position, the sidewall of the mold ending up to be the uppermost will be removed, and the element is lifted away from the table using lugs provided on its sides. The position of the upper sidewall must be movable depending on the size of the element to be cast, and for that purpose, removable sidewalls can be used. By means of removable and adjustable sidewall parts also door or window openings can be formed to the element in desired places.
The use of magnets for fastening removable sidewalls of the mold is known in the art, and they are especially suitable for fixing a sidewall as they attach to the flat steel surface of the mold. To provide a strong attachment of the sidewall, strong magnets must be used effecting a bond strength of e.g. 15 kN. European Patent publication EP-A-1 075 917 discloses a magnet unit fixing to the counter part provided to the sidewall through an oblique protrusion or jaw of its front surface attaching to the respective oblique groove of the counter part. The front surface of the magnet unit is manufactured so that it is precisely in the angle of 90° C. with respect to the casting bed, when the magnet unit is fixed to the sidewall, whereby the front surface, due to the wedging effect the fixing system is characterized of, attaches to the back surface of the sidewall and keeps the sidewall always vertical. The magnet unit of EP-A-1 075 917 is provided with a tillable magnet that in its lower position can be fixed to the casting bed or turned up in the readiness position.
In addition, the casting bed usually comprises immovable lower and end walls at the edges of the casting bed, said walls being fixed by means of hinges to the casting bed. These sidewalls fixed to the casting bed with hinges have a heavy construction, and it is labour-consuming to remove them from the casting bed and to change them. It is not possible to form different through-holes required for these sidewalls e.g. by the reinforcing without breaking the side molds. And because the sizes of the production runs of the elements to be cast are very small, the forms of the elements to be cast must be changed frequently, whereby the sidewall sizes of the casting mold must be correspondingly changed. For these reasons the casting molds made of wood and veneer are increasingly used, causing big material consumption due to the small production runs.